Manufacture of phenol and allied products.



UNITED srntgisrnrnnr OFFIC,

ROGER N. WALLACH, 0F WAPPINGERS FALLS, NEW YORK.

MANUFACTURE OF PHENOL AND ALLIED PRODUCTS.

No Drawing.

To all 107mm, it IN (11 concern: I

Be it known that I, Roenn N. WALLACE, a subject of the Emperor of Germany, and a nativeof Alsace, residing at Wappingers Falls, in the county of Dutchess, State of New York, have invented certain new and useful Improvements in the Manufacture of Phenol and Allied Products, of which the following is a specification.

My present invention in its broadest aspect relates to an improved process for subjecting organic sulfonic acids and salts to alkaline fusion, and, in its more specific aspect, the invention relates to an improvement in one step in the recess of manufacturing phenol (C OH), naphthol ((3, 11,011), resorcin and other 0x3 products. For the purpose of describing certain detailed or specific embodiments of the invention I shall confine myself hereinafter to the discussion of its application to the manufacture of phenol or naphthol, but it is to be understood that I do not limit myself to these particular products in my broader claims.

Hitherto in the manufacture of phenol,

for instance, at one stage of the process, a

benzol sulfonic salt is added to caustic alkali fused at a temperature of about 300 degrees (3., and the resultant mixture of phenolate, caustic soda, sulfite, etc., is treated for production of the phenol in a well known manner with which my present invention is not concerned.

For this purpose the benzol sulfonie salt has hitherto been evaporated to substantial dryness by the heat of live steam, and the cakes, flakes or powder resulting have been added to the fused caustic soda, and stirred through the same at a temperature of about 300 degrees C. This process, as hitherto carried out, presents a number of obvious disadvantages incident to the evaporation of the sulfonic salts, all of which have been submitted to heretofore because it hasbeen supposed that the addition of the original solution without evaporation, directly to the fused alkali would be impracticable, owing to dangerously violent reaction, or the causing of excessive cooling of the fused alkali, thereby preventing reaction and creating mechanical difficulties.

I have discovered that this direct addi- Specification of Letters Patent.

Patented Aug. 6, 1918.

Application filed January 12, 1918. Serial No. 211,654.

tion of the aqueous solution of sulfonic salts is entirely practicable, and that this process has very important advantages hereinafter pointed out.

My improved process may be carried out by the use of any appropriate apparatus such as will occur to those skilled in the art, the only essential elements being an appropriate apparatus for the production of the sulfonic salts, another for the fusion of the caustic alkali, and preferably a pipe and valve for conveying the former to the latter.

Obviously the sulfonic salt solution, after manufacture, may be stored in tanks prior to introduction into the fused caustic alkali, keeping it at a temperature at which the concentrated solution will not start to crystallize.

In the manufacture of phenol, the saturated benzol sulfonic salt solution made in the manner usual in the prior art is preferably heated to a temperature of about 100 degrees 0., so as to produce as concentrated a solution as possible; the caustic alkali having been fused and kept at a temperature of about 300 degrees (1., preferably in a vessel suitably covered to prevent loss due to ebullition during the reaction, the hot saturated sulfonic solution is led into the vessel containing the alkali through a pipe line. There is no limit to the rapidity with which the saturated sulfonic salt solution may be introduced into the fused caustic alkali, except that care must be taken not to lower the temperature ofthe fused liquid materially below 280 degrees C. It is clear that my invention is not limited to the use of a pipe line, since the sulfonic solution might be poured into the vessel containing the alkali.

The proportions used will be such as have already been employed in this art, and it will be convenient to prepare the proper quantities of the sulfonic salt and caustic alkali in their respective vessels, so that when the vessel containing the salt solution is emptied, the appropriate mixture will have been produced within the vessel of caustic alkali. The mixture should be stirred during the reaction, and the operation will be completed shortly after the last of the salt solution has been added.

My process is productive of the following very voluminous dry or semi-dry product.

I avoid these losses and the added labor involved.

2. The dry or semi-dry sulfonic salts often form cakes which are dissolved with some ditiiculty in the fused alkali, while in my process this difliculty is avoided, and

there 1s an lmportant saving of time, as the liquids mingle instantaneously and uniformly.

3. My process saves fuel because the heating is by directapplication of fire to the sulfonic solution instead of by the use of expensive live steam in the evaporating apparatus. Moreover, the final evaporation in the older process is very ineiiicient, due to the thickening of the liquid. Furthermore, by addition of a hot solution instead of a cold salt,less fuel is required to bring the addedsalt up to the reaction temperature.

4:. Economy is achieved in cost of apparatus, in space, labor and repairs.

5. The results of the final reaction are better and more uniform, since the shortening of the time of fusion reduces the proportion of objectionable tarry impurities.

6. In the evaporation process hitherto practised, accidental burning up of the whole fusion through overheating of the thick mass often occurs, since it is obvious that the addition of the dry or semi-dry salt causes thickening and cooling, and makes it necessary to drive up the fusion temperature. This, together with agitator troubles, is avoided by my liquid-mixing process.

7. Economy is achieved by permitting a lower temperature of fusion. In the old process it has been generally customary and necessary, in order to insure complete fusion, to drive up the final temperature about 20 degrees C. above the temperature necessary for the fusion reaction. This driving up is avoided by my process.

It is to be noted in this connection that there is always a material charring in the old process, which I avoid entirely by the very fine division of the salt as it is presented to the alkali. The water of solution evaporates practically instantly on touching the hot alkali. As it is previously heated to degrees C. the minimum of cooling results.

8. My process makes it possible to feed as gradually and uniformly as desired while fusing in closed vessels, either at ordinary, reduced or increased pressures, with exclusion of air. Gradual feeding Which is highly beneficial and which is practised in open vessels has heretofore been imme eor practicable When fusing in closed vessels. One of the merits of my invention is that this'operation is not only made possible but very simple. This circumstance in itself is highly beneficial to the quality, cost of the product obtained.

Furthermore, I am enabled accurately to regulate the fusion temperature by controlling the stream of salt solution; increasing it as the temperature rises and vice versa. It is obvious that the convenience and ease of handling are greatly enhanced, since only one, or perhaps two, valves are used in the pipe line.

9. Economy is also achieved in the saving of material. In the process under the old methods it is necessary to have a large excess of caustic alkali. I have found that the excess of caustic alkali necessary for the completion of the reaction can be materially reduced by the use of my process.

Instead of the simpler sulfonic salts above specified, I may use naphthalene mono-sulfonic salts, anthraquinone sulfonic salts,

benzol poly sulfonic acids, naphthalene poly-sulfonic acids, anthraquinone-poly-sulfonic acids, or substituted sulfonic acids, etc., or their salts may be used. In short, any .or-

ganic sulfonic acids or saltscan be subjected to an alkaline fusion reaction by my process. The fusion temperature in each case will be that customary for each product, or from 10 to 20 degrees C. lower, owing to avoiding the necessity for driving up as above stated. The caustic soda generally employed may be replaced in whole or in part by caustic potash, calcium oxid, barium oxid, etc., as well understood in the prior art.

What ll claim is:

1. The process of caustic alkali fusion of organic sulfonic acids in the form of their salts which consists in adding an' aqueous solution of such product directly to a mass of the fused caustic alkali.

2. The process of caustic alkali'fusion of organic sulfonic acids in the form of their salts which consists in heating an aqueous solution of such productand adding the same while hot directly to a mass of fused caustic alkali.

3. The process of caustic alkali fusion of sulfonic salts which consists in heating an aqueous solution of such salt and feeding the same in a stream into a mass of fused caustic alkali.

4:. The process of caustic alkali fusion of sulfonic salt which consists in heatingan aqueous solution of such salt, conveying the same in a stream into a mass of fused caustic alkali, and controlling the flow of such stream to counteract variations in the temperature of reaction.

5. As steps in the manufacture of pheyield and nols, preparing an aqueous solution of a sulfonic salt, and adding the same to a mass of caustic alkali in a state of fusion.

6. As steps in the manufacture of phenols, preparing a concentrated aqueous solution of a sulfonic salt, at a temperature of about 100 degrees C. andadding the same to fused caustic alkali at a temperature of about 300 degrees C.

7 As steps in the manufacture of phenol, preparing an aqueous solution of benzol sulfonic salt and adding the same to fused caustic alkali.

8. As steps in the manufacture of phenol, preparing a concentrated aqueous solution of benzol sulfonic salt at a temperature of about 100 degrees C. and adding the same to fused caustic alkali at a temperature of about 300 degrees C.

9. The process of caustic alkali fusion of sulfonic salts which consists in heating an aqueous solution of such salt and feeding the same into a closed vessel containing a mass of fused caustic alkali.

10. As steps in the manufacture of phenols, preparing an aqueous solution of henzol sulfonic salt and feeding the same into a closed vessel containing fused caustic alkali.

In testimony whereof, I have afiixed my signature to this specification.

' ROGER N. WALLACH. 

